The general goal of this proposal is to determine genetic repair capabilities with selected segments of our population. Due to previous findings, the major emphasis in this grant will be to extend the preliminary observations that systemic lupus erythematosis (SLE) patients have an impaired repair response to DNA damaging agents such as 4-Nitroquinoline oxide. In addition to SLE studies, we will investigate the genetic repair response of patients given cytotoxic drugs for cancer therapy, and the possibility of detecting repair induction from body fluid of human subjects and experimental animals exposed to various chemicals.